fills, it draws water from the supply pipes. If someone is showering at the same time, the two fixtures may compete for available water, particularly if the washer uses hot water.
This can cause temporary changes in pressure or temperature. In a well-designed plumbing system, these changes may be barely noticeable. In an older home or a system with limited capacity, they can be more obvious.
Electrical safety is a separate matter. Washing machines must be properly installed, grounded, and protected according to applicable electrical requirements. Because bathrooms are wet